SS9301-SP 930504 (3)
Tunnel design
General design factors · ~-"
Tunnel loads var5' widely in
magnitude and classification,
depending on the soils en-
countered and construction
practices used in driving the
tunnel. Loads encountered ~
during the tunneling operation
are entirely different from
those on the finished and
grouted tunnel.
Once construction is fin-
ished and the tunnel has been
grouted, a more uniform load
distribution develops around
the tunnel. These final loads
consist of dead and live loads.
Since loads that develop dur-
ing construction depend on the
tunneling procedure and soil
conditions, they are extremely .
difficult to predict. The tunnel-
lng contractor often copes with
slough-ins, water-bearing soil
pressures and other forms of
point loading. Handling these
temporary overloads requires
proper equipment and good
techniques to maintain the
correct shape of the lining. Crew working within the safetY' zone created with the Tunnel Liner Plate.
Contractors also rely on suita-
bly engineered liner structures
with high bending resistance ~ /./ :, ,.
(stiffness) to resist point-type ~ . ~ ' ~~"~/
loads that are common dur- ~ ~/// ~tX J
ing construction, it is in the
designer's interest to make .... Tunnel Ring -- ~Tunnel Ring --
reasonable provision for these //~//~'~~X~' J ~X. / '~
construction loads. / ~ 'x
The design engineer's at .... . ' '-,
tention is logically directed , ~.x ,
toward calculating final loads Construction Load Final Load
and then designing and specify- . .............................
lng adequate support for them.
But the designer should be
aware that construction loads
are generally the control,
especially in soft ground or
hand-mined tunnels.
Comparison of 2-flange
and 4-flange liner plate
Differences
There are important differ- ~ ~
ences in the two types of plate.
It is essential that the designer
recognize these differences
in comparing 2-flange liner
plate with 4-flange plate for a ~ Plate Lap Joint Tunnel Liner Plate
specific tunnel.
Two-flange liner plate is a Deep, full length corrugations and lapped joints for more effective
fully and deeply corrugated stiffness and ring compression.
plate with the corrugation ~ ~
extending through the offset
lapped longitudinal joint. When
offset liner plates are assem-
bled, the resultant liner is just
like a corrugated steel pipe
with deep corrugations encir- ~ Plate Butt Joint Tunnel Liner Plate
cling the structure.
On the other hand, 4-flange Shallow corrugations and hinged joint.
plates have a shallow corruga-
tion with a turned-in flange on What's the practical meaning tain thickness of 2-flange plate,
all four sides. The corrugations of all this? then this requirement in the
do not extend the full length of During construction, a tunnel 4-flange is a thickn, ess whose
the plate, liner is often the only protec- moment of inertia is approxi-
These features account for tion workers and equipment mately twice that of the speci-
the key differences in the tun- have against slough-ins, grout- fled 2-flange (See Table I).
riel liners. Th.e bending strength lng pressures, and other con- Conversely, if the minimum
of the deep corrugated cross centrated loads. To provide bending strength is said to be
section is, of course, greater protection against such forces, a certain thickness of 4-flange,
than the shallow stamped the minimum required in
cross section. In addition, the a liner plate needs ample
stiffness. How much stiffness 2-flange need have a moment
hinging action of the typical depends on the size of the of inertia only half that of the
4-flange joint further reduces tunnel, the soil around it, the specified 4-flange.
the actual stiffness of the as- tunnel method used, the over- Minimum installation stiff-
sembled liner rings, burden, and other factors, ness determines the weight of
The end result is that the It is in assessing the stiff- plate used in many cases. When
2-flange liner is a much more it does, 2-flange liner plate will
ness requirement that you
rugged tunneling tool. Two- generally provide the required
flange liner has effective stiff- should recognize the differ-
ence in 2-flange and 4-flang~ stiffness more economically
ness that is more than twice that plate, if the minimum stiffness than 4-flange.
of the same thickness of 4-flange.
These facts are confirmed requirement is said to be a cer-
by AASHTO "Design Specifica- Table !*
tion for Tunnel Liner Plate." Equal Stiffness of 2-Flange and 4-Flange Liner Plate
This specification shows that 2-Flange Equivalent 4-Flange
while 2-flange plates have up Thickness Thickness
to 30% more seam strength
than 4-flange plates of the same 0.075 0.179
thickness, the effective stiffness 0.105 0.239
of 2-flange is more than 100% 0.135 0.3;'5
greater than the same gage * Based on AASHTO Design Specification. Section 16. paragraphs 16.3.3 and 16.5
4-flange. where 2-flange elfective moment of inertia--l--is 2.22 times 4-flange 1.
3
AASHTO design
(Per AASHTO "Design
Specifications for Tunnel
Liner Plates," Section 16.)
Loading considerations--The
supporting capacity of a non- -.
rigid tunnel lining such as a
steel liner plate results from
its ability to deflect under load
sothatsiderestraintdevel- ,~~.. ~
oped by the lateral resistance '
of the soil constrains further
deflection. Deflection thus .-
tends to equalize radial pres-
sures and loads the tunnel
liner as a compression ring.
The load carried by the --~.. -
tunnel liner is a function of the .........
type of soil. In granular soil,
with little or no cohesion, the
load is a function of the angle
of internal friction of the soil ,~.~
and the diameter of the tunnel. ~,.
In cohesive soils such as clays .
and silty clays, the load car-
·
ried by the tunnel liner is
dependent on the shearing .,,..: .,. .
.~.
strength of the soil above the :: - ·
roof of the tunnel.
A subsurface exploration
program and appropriate soil ~ ' ~ '~ -
tests should be performed at
each installation before under-
taking a design. Tunnel crew makes final holt tightening and inspection before grouting.
Loads~External load on a cfi- Where: \Vhere:
cular tunnel liner consisting of P = The external load on the C,: = Coefficient for tunnel
tunnel liner plates may be pre- tunnel liner, liner (see Chart I).
dicted by various methods, P. = The vertical load at the \V = Total (moist) unit weight
including actual tests. In cases " level of the top of the of soil.
where more precise methods tunnel liner due to live D = Horizontal diameter or
of analysis are not employed, loads (see Table II for span of the tunnel.
the external load, P, can be approximate values). H = Height of soil over the
predicted by the following: P,:--The vertical load at the top of the tunnel.
1. If the grouting pressure is level of the top of the In the absence of adequate
greater than the computed tunnel liner due to dead borings and soil tests, the full
external load, the external load. overburden height should be
load, P, on the tunnel liner Values of P,~ may be calcu- the basis for P. in the tunnel
shall be the grouting pres- lated using Marston's formula liner plate design: (P,. = H\V).
sure. for load or any other suitable
2. In general, the external load method.
can be computed by the P -- C,. WD
formula ':
P = P~ + P~
4
Chart I
Values of Coefficient Cd
Table I!
Live Load Pressure at Tunnel Top (Pt)
Highway Railroad
Height of Cover H 20 Load Height of Cover E 80 Load
(in feet) (Ib./ft?) (in feet) (lb./ft.2)
4 400 4 3,000
5 250 5 2,400
6 200 8 1,600
7 175 10 1,100
8 100 12 800
9 90 15 600
10 75 20 300
30 100 AASHTO Design is continued
on Page 6.
AASHTO design
Design criteria
The following criteria must be
considered in the design of
liner plates:
· Joint strength.
· Minimum stiffness for
installation.
· Critical buckling of the
liner plate wall.
· Deflection or flattening of
tunnel section.
Joint strength
Seam strength for liner plates should be sufficient to withstand the thrust developed from the total
load supported by the liner plate. This thrust, T, in pounds per lineal foot is:
T= PD 2
Where: P= Load as defined on Page 4.
D= Diameter or span, in feet.
Thrust, T, multiplied by the safety factor, FS, (FS = 3, recommended) should not exceed the ultimate
seam strengt, h shown in Table IV on Page 10.
Minimum stiffness for installation
The liner plate ring should have enough rigidity to resist the unbalanced loadings of normal con-
struction, including grouting pressure, local slough-ins, and miscellaneous concentrated loads. The
minimum stiffness required for these loads can be expressed for convenience by the formula below.
'" It must be recognized, however, that the limiting values given here are only recommended minimums.
Actual job conditions may require higher values (greater effective stiffness). Final determination on
this safety factor should be based on intimate knowledge of the project, soil conditions, and practical
experience.
The minimum stiffness for installation is determined by the formula:
El
Minimum stiffness = ~
D2
Where: D= Diameter in inches.
E= Modulus of elasticity, psi (29 x 106).
I = Moment of inertia, inches to the fourth power per inch.
El El
For 2-flange = ~ = 50 minimum For 4-flange = ~ = 111 minimum
Da D?
[Note: The values above are without safety factors. An appropriate safety factor is recommended, j
The added installed cost of a tunnel is typically very small.]
6
Critical buckling Deflection or flattening
Wall buckling stresses are determined from the following Deflection of a tunnel depends
formulae: significantly on the amount of
over-excavation of the bore
For diameters less than r__ 24E . and is affected by delay in
f-- backpacking (grouting) or in-
k
adequate backpacking. The
- magnitude of deflection is not
(__)2 primarily a function of soil
f = f - fu2 x in psi modulus or the liner plate
c u _48E _ properties, so it cannot be
computed with usual deflec-
tion formulae. Where the
For diameters greater than r 24E tunnel clearances are impor-
m ~- rant, the designer should
k /~ fu oversize the structure to
provide for normal deflection.
12E
fc = 2 in psi
('"~') [Sizes shown in this catalog
are to the neutral axis, not the
inside diameter.]
Where: f~= Minimum specified tensile strength, psi.
f~ = Buckling stress, psi, not to exceed specified yield [Minimum Cover
stre. ngth. A minimum limit of four feet,
k = Soil stiffness factor, will vary from 0.22 for soils with depending upon material,
O >15' to 0.44 for soils O < 15'. should generally be used to
D= Pipe diameter, inches, prevent loss of roof material.]
r = Radius of gyration of section, inches/foot.
E= Modulus of elasticity, psi.
Design for buckling is accomplished by limiting the ring compres-
sion thrust, T, to the buckling stress multiplied by the effective
cross-sectional area of the liner plate, A, divided by the factor of
safety:
T = fcA
FS
Where: T =Thrust per lineal foot.
A = Effective cross-sectional area of liner plate, in.2/ft.
FS= Factor of safety for buckling.
Recommended FS = 2
Design example
Two-flange liner plate is After installation and Sample computation
designed to furnish high con- back grouting, the ring must Assumed
tinuous ring stiffness and high possess sufficient compressive H= 20' E 80 Live Load
compression joint strength, wall strength and buckling B,= Dia. = 84"
Continuous ring stiffness in resistance to carry the squeez- (see Marston's theory
2-tlange liner plate prevents lng effect of final loading on for
hinge effects at longitudinal the ring. These loads approach W= 120 lb./cu, ft.
joints. This superior bending a pattern of symmetry and (saturated clay)
strength is useful to the thus place the 2-flange liner K = 0.22
contractor in helping maintain plate ring primarily in E = 29 x 106
structure shape during instal- compression, f = 45,000 psi
lation and grouting, fu_ 33,000 psi
Since stiffness is so often the control for plate thickness, the calculation for it will be done first.
!. Minimum Stiffness for installation (construction load design)
The design engineer should use an appropriate safety factor for stiffness. Final determination
of this safety factor should be based on intimate knowledge of the project soil conditions and
the contractor's experience. In this example a factor of safety of 3 was selected as used by
AASHTO for seam strength.
Stiffness = E1
D2
To provide FS = 3, set minimum stiffness equal to 3 x 50 = 150
D-~ x (Minimum Stiffness) (84)2 (150)
Find required I = = = 0.0365 in.?in.
E 29 x 106
Select 0.1046" 2-flange plate with I = 0.0491 in.4/in. (from Table Iii).
il. Final load design
1. Find load
H 20
= -- = 2.9 Now use Chart ! (on Page 5) to find that Cd = 1.9
D 7
Pu = Cd WD
Po -- 1.9 x 120 x 7 = 1,596 lb./ft.2
From Table 11, PL = 300 lb-/ft.2
P = Pd + PL = 1,596 + 300 = 1,896 lb./ft?
8
2. Joint strength
Actual thrust
T -- P x D/2
-- 1,896 x 7/2
= 6,636 lb./lin, ft.
Minimum safety factor required (AASHTO) = 3
From Table IV 0.1046 2-flange plate (ultimate seam strength is 30,000 lb./lin, ft.)
Check safety factor 30,000/6,636 = 4.5
4.5 :, 3.0, therefore the safety factor for 2-flange liner plate is sufficient.
3. Critical buckling
From Table III, radius of gyration Ur" for 0.1046 plate = 0.604
r 24E 0.604 24 x 29 x 106
-- = = 341
k fu 0.22 4s,ooo
) Tunnel diameter (84") is less than 341, theref°reusefc= f~- f~2 x ('KD'~?
_48E x. r J _J
(45,000)z f 0.22 x 84
45,000
x~ _ = 43,638
48 x 29 x 106 ~. 0.604
This exceeds the yield point of the corrugated plate (33,000 psi), therefore use
= 33,000 psi.
beck safety factor for 0.1046 2-flange plate where A = 1.618 in.Z/ft. (from Table liD.
A x f (1.618) (33,000)
FS = ~ - = 8.0
T 6,636
Minimum required safety factor is 2.
8.0 > 2, therefore 2-flange 0.1046 plate is safe in buckling
a-Flange Design: Appropriate 'T', "r', "A' and minimum stiffness values for
4-flange are necessary to find the thickness of 4-flange plates.
Data on 2-flange liner plate
Table I!I
Properties and Dimensions
of 2-Flange Tunnel Liner Plate
Mom~t
Section of Radius Approx. Plate Wt-
'~ Ar~a Modulus Inertia og Including
in in ] la Gyra- X Boils, in Pounds
Thickness ~i. lu. Inchess] Inches4 ~
ia Per Per Per in 12 Pi. 14 Pi. 16 ISl.
Inches Lin. Ft. Lin. In. Lin. la. Inches Plate Plate Plate
0.0747 1.149 0.0323 [ 0.0345 0.600 0.757 25 28 31
0.1046 1.618 0.0457 0.0491 0.604 0.779 33 37 42
0.1345 2,086 0.05~ 0.0640 0.607 0.799 41 47 52
0.1644 2.559 0.0726 00795 0,610 0.819 49 56 63
0.1793 2.796 0.0798 0.0877 0.613 0.831 53 61 68
0.2092 3,263 0.0928 0.1031 0.616 0.848 61 70 79
0.2391 3.740 0.1065 0.1193 0,619 0.869 70 80 90
Full depth corrugation. X = Distance from outer lace lo neutral axis. in :nches.
Table IV
Ultimate Longitudinal Seam
Strength o! 2-Flange Liner Plate
In lb./lin, ft.*
Speciflod 0'0~47 0'1046 0'1345 0'1644 0'1793 0'2092 0'2391 ~
Thickness
Strength 20.000 30.000 47.0~ 55300 62.000 87,0~ 92.000 ~
lb./lt. Section A-A
*In 0.0747 through 0.1793 thickness structures, longitudinal bolts
I are ASTM A307, s/s" diameter by 1 :.:4" long. In 0.2092 and 0.2391
. thicknesses, bolts are ASTM A449, 5/8" diameter by 1 '/2" long. The L~Varies Neutral Axis
i nuts are ASTM A307 Gr. A.
x--
- ~-'-"'-"";s:' ' ..... -,'
Section
· r-'~
i ............................................. .....
, ~ . Bolts are staggered to provide more strength g ~
: ,O1 s~.o. c~
-' IF---~-- = :' --- .F - ----,~ "~4,-_-,,,.-~4;:-,'~--.-.-52'_ --,,' -"-'"~.---'~--.~:-.- .~.,- -- ~ ~ =L"~"~ ~ a t: ·
- -- .--- .... ,-v.',- ? · ....
L B Plan L~ a
covering Length ~-~__~ '~x
3~:/~ :; sStOr~ie ~......~/'~~ Minimum Radius
6 lat lu d) 0.1793 Thickness and Lighter 24"
0.2092 Thickness 30"
~evaflon 0.2391 Thickness 30"
lO
] Grout plugs
· 18" ~ For pressure grouting, liner
sections may be supplied with
9"
~ 9" ~ two-inch standard pipe half
rF~..~ ~]~ /--~--------~ couplings welded into a hole in
the center corrugation. Cou-
_~ plings are fitted with threaded
Coupling plugs.
2" C.I. Plug
I _----~~ Tapped grout holes
As an option, grout holes may
~ be supplied as threaded holes
~ on 12-gage and heavier plates
~ for two-inch standard pipe
located in the side of the
center corrugation, in the
· 18" · middle of the plate.
\ Pi Plate Z
16 26S/s''
) b 14 ' 23'/2"
Location of Tapped Hole 12 203/8"
Location of coupling or tapped hole
along the plate length.
. ~-'~,~. . .. .
., .,- . -' .- - -<,. ~:~ . ~. .
· .. ---~.,,~.~ . ;.~.. ,.~,~, 6 Each 1'
,_. '~_~, ~' .~.~ ..~ F:", ~ ·
":' "~' %'~~':~¥"':~'"'~,; ~,.-'~.z~.-~ ;-.. "-". 1~/,~'' :?"
:,r'.~ -' ':"~',~, ~- ". ~, ': .... ,,~ ..
:.~.:. ~'~,~., .. ,~-.
:~, ~...s~-~ .... ,¥,...~ -
~li~~~ ..--,. · ...-- -
· ~I~_~'~1~:-~:,.--';'-
. · -. ...~.-..~:~._ -.
-~I ~'~L-' ..'... '" .., ~. - ~-'x'
-~*** ,~:,c,*.,.,,~,~ .... '" .z : 7-Gage Black or Galvanized
.~'~.'. ~."~.. ~... . -~ ] 18" Length Also Available
Base channel for arches
Base plates are used to support
arch-shaped tunnel liners.
11
Circular structures of
Contech Tunnel Liner Plate
Table V
Table of Available Diameters and Dimensions,
Including Numbers of Specific T~l~es of Plates Required
-*- : ~ : i ~i Plates per Ring
' Plates Plates Plates Ii ~ : ~
_ ._ ; e % i: Plates Plates Plates
~ '
,18 45-.~ 4~'~ 132 i 4 1 2 I 118 115~. i 119'~ ' 77.5 8 5 I I 1
$0 47:-i 51:i 1-1.3 4 2 I I 120 117~'~ !21:., 81} I 8 4 I 1 2 1
$2 4~-~ 53:., 15.5 4 2 I I !~2 119L, 123~i 82.9 8 1
54 51 :.-~ 55:~ 166 4 I I 2 124 121[', 125-..i $$8
56 53]..~ 57:/, 17.9 4 I 2 1 126 123s4 127~,~ 88.5 8 I I 6
58 55~.,~ 59~., 19.1 4 2 i I 128 125;A 129~ 90.5 8 I 6 I
~ 57% 61'~ 20.4 4 2 I I 130 127~ 131~,~ 93.9 9 7 I I
62 59:,~ 63~,'~ 21.8 4 I I 2 132 129% 133~'~ I 96.~ 9 6 ! 1
1
64 61:, 65-.-~ 23.2 4 I 2 I 134 131'.-~ 135..~ 9~ 9 ~ 5 [ I ~ 2 1
66 63', 67:, 24 6 5 I I 3 136 133'~ 137:., 102.8 9 ] 4 ] ~ 3 1
I
68 65-* 69-~ 26 I 5 I I 3 138 1:~5:* 139:* 105.8 9
70 67:-~ 71-,~ 277 5 I 3 I 140 137;~ 141-.. i 108.8 9 1 I 7
72 69~..~ 73:,~ 29.2 5 3 I I 142 1391z~ 143L~ I 11.9 9 I 7
74 71'A 75~4 30.8 5 3 I I 144 141 ~/* 145~:~ 115.0 9 7 I
76 73% 77~.~ 325 5 1 I 3 146 143% 147% 118.1 10 7 I I
78 75V~ 79~.~ 34.2 5 ! I 3 148 145:4 1497~ 121.3 10 6 2 I ~'~
~ 77~.~ 81:.'~ 36.0 5 1 3 I 150 147'.-~ 151:,~ 124.5 10 5 3 1
82 79:* 83L-~ 37.8 6 I I 4 152 149'.~ 153'~, 128.0 I0 4 4 1
~ 81:, 85:,~ 39.7 6 I 4 I 154 151~'~ 155:4 131.5 10 1 I I 7
86 83-~ 87 :.-~ 41.6 6 4 I I 156 153~* 157~'* 135.0 l0 I I 8
~ 85:,~ 89~,~ 43.5 6 4 I I 158 155% 159% 138.5 l0 ! 8
~ 87~A 91~.~ 45.4 6 3 I 1 I l~ 157V~ 1619~ 141.9 10 8 I
92 89'A 93 L.', 47.4 6 I I 4 162 159~ 163% 145.5 11 7 2 1
94 91:.., 95:-~ 494 6 ! 1 4 I~ 161~..~ 165:,* 149.0 11 6 3 1
96 93'~ 97:-~ 5].5 6 I 4 I 166 163L~ 167:.~ 152.6 II 5 4 1
98 95;, 99'~ 536 7 I 5 I 168 165:., 169', I 156.3 11 4 5 1
I~ 97% 101:.~ 55.8 7 5 I I 170 167~.~ ]71'~ i 1~.0 11 1 I I 8
102 99'., 103:.-~ 58 I 7 5 I I 172 169'~ 173', I 163.8 11 ,* ] I 9
l~ 101 :..~ 105:,~ ~.3 7 4 I 1 I 174 171% 175:/* 167.6 11 I I 9
I~ 103~.~ 107% 62.6 7 1 I I 4 ]76 173:,~ 177~ 1715 11 I 9 I
!08 105~.-~ 109',~ 65.0 7 I I 5 178 175~ 179~/~ 175.5 12 7 I 3 1
]!0 107% IIIL'~ 67.5 7 I I 5 I~ 1779~ 1gu/* 179.5 12 6 I 4 1
] 12 109:~ 113: ~ 70.0 7 I 5 I *~'pe of of[~ at ends ol plate. N = No Off~l: S = Single Olfset; D = Double
114 [ I I ~. l 15--~ 72.5 8 6 I I Oif~t. Diam?e~ are avmlable a~we those shown in the ~me pattern. Structures
116 113~.~ 117'~ 75.0 8 6 I I designed for 4 Pi (12~.~ ") stagger in ~ongitudinal seams in alternate rings.
"~e clearance sole on ~ge [3.
S~ci~ sha~s
o[ Contech Hner Plate
,._.
Arch Ho~eshoe Pipe-Arch Underpass
Table VI
Data on Contech Liner Plate Elliptical Underpasses
Inside Neutral Axis No. Plates Required
Neutral Axis R~ R, 12 Pi 14 Pi 16 Pi Rectangular Clearancess
Periphery,
.No. Pi Inches Height Width N S D N S D N S D
I 80 87:.4 ~ 65;A' 30~ 60' I I 4 4'0" x 5'0~
2 84 91:.4~ 69:.-'~" 32" 62' I 4 I 4'0" x 5'6". 4'6' x 5'0~
3 88 95',~" 73~,4" 34" 64" 4 I ! 4'0" x 6'0". 4'6" x 5'6"
4 92 99~,i~ 77%' 36' 66' I ! 4 4'0" x 6'6". 4'0~ x 6'0'. 5'0' x 5'6'
6 100 107~.~# 85:..3' 40' 70' 6 I I 4'6' x ?'0". 5'0' x 6'6". 5'6' x 5'9'
7 104 Ill~A'' 89L~~ 42~ 72~ 4 I 2 i 4'6'xT'6",5'0~xT'0'.5'6'x6'5'
8 112 119~A' 971A' 46' 76' 4 1 2 1 5'0~x8'0".5'6"xT'5',6'0'x6'9'
9 120 127~A~ 105~.'i' 50' 80' 4 1 2 1 5'0' x 8'10", 5'6' x 8'4', 6'0' x T'10
Other sizes available on request.
N = No Offset; S = Single Offset; D = Double Offset
Offset Note~
l. Additional sizes of elliptical
tunnel liner plate formed 10%
elliptical or less are available
if required.
2. Where the tunnel clear-
: ,. ances are important, the de-
l signer should oversize the
i.,,.~-...~--~-.~,,,] structure to provide for
normal deflection. Sizes
~ i ~ shown in Table V are to the
~._i ,/// neutral axis, not the inside
diameter.
Double Offset
13
pecit;cation guidelines
Scope Grout holes shall be two Mining
These specifications cover inches in diameter and shall Care should be exercised to
cold-formed steel tunnel liner be provided as shown on the mine as neatly as possible to
plates, fabricated to permit in- plans to permit grouting as the eliminate voids or overbreaks
place assembly of a continuous assembly of the liner plate and obtain maximum plate-to-
steel support system. The proceeds. Ali grout holes shall ground contact. Neat mining
tunnel or re-lined structure be tapped or welded with reduces the quantity and
shall be of the neutral axis dj- coupling. Tapped holes shall frequency of back grouting,
ameter and/or shape and gage be provided with a plug helps maintain tunnel shape,
as shown on the plans unless screwed in place, and puts the inherent strength
specified otherwise. The liner of liner plate to optimum use.
plate design shall be in accor- Galvanizing and coating In unstable soils it is impor-
dance with the design criteria Material to be galvanized shall tant that tunnel headings be
for joint strength, stiffness, be zinc coated in accordance continuously protected against
buckling, and deflection as with ASTM Specification A123, any loss of ground materials.
defined in the AASHTO Stan- except that the zinc shall be Poling plates, breast boards,
dard Specifications for Highway applied at the rate of two shields, and soil solidification
Bridges, latest edition, with ounces per square foot total have been successful in con-
appropriate safety factors, for both sides, trolling tunnel headings under
Material to be bituminous unstable conditions. Use of
Material coated shall conform to any one or a combination of
The liner plate shall be fabri- AASHTO Designation M190. these methods may be neces- ~X
cated from structural quality, sary for the proper and safe
hot-rolled carbon steel sheets Bolts and nuts advancement of the tunnel.
or plates conforming to ASTM Bolts and nuts shall be of the
Specification A569. Plates shall diameter and length as recomo Stiffness
be accurately curved to suit mended by the manufacturer. Wherever the soil becomes
the tunnel cross section and When galvanized bolts and very unstable, the loads on the
shall be of uniform fabrication nuts are required with galva- tunnel tend to increase. Maxi-
to allow plates of similar curva- nized liner plate, the galvaniz- mum ring stiffness under these
ture to be interchanged, ing shall conform to ASTM conditions becomes of prime
All plates shall be punched Specification A153. importance.
for bolting on both the longitu-
dinal and circumferential Design Grouting
seams and shall be so fabri- Liner plate shall be designed in After rings have been installed,
cated as to permit complete accordance with the AASHTO back grouting to fill any voids
erection from the inside of the "Design Specification for should be conducted in a
tunnel. Circumferential hole Tunnel Liner Plates," Section manner to prevent buckling or
spacing will be a multiple of 16. Appropriate safety factors shifting of the liner ring. The
the plate length to allow stag- for seam strength, buckling grouting crews should be
gering of the longitudinal seam. and stiffness should be used. scheduled as soon as practical
Circumferential bolt spacing behind the mining operation.
shall be 12 I/2" unless otherwise Installation Good back grouting practice
specified. Liner plate shall be assembled ensures a proper job and helps
in accordance with the develop the full supporting
manufacturer's instructions, strength of the liner ring for
final loads. ~.,
14
i
!
t~
~.1 '
"" -
. -.
' ' '...'
Liner plate can be used to reline railroad tunnels o[ t,arious shapes.
An answer to your
site development problems
There is a size and type of Contech product to help Box Culverts...For maximum water flow under
solve almost any civil engineering site development minimum headroom. Aluminum's light weight means
problem. You can use these products with complete con- easier installation.
fidence in their strength, durability, and economy. They SUPER-SPAN Structures...Economically and aestheti-
have been tested and proven by a half-century of re- cally advantageous for new and replacement bridges.
search and practical field experience. Bin-Type Retaining Walls...For unstable slopes, limited
HEL-COR Corrugated Steel Pipe and CORLIX rights-of-way, shore and bank protection.
Corrugated Aluminum Pipe...These products are Liner Plate...For constructing new utility tunnels and
designed for use as drainage culverts, storm sewers,
stream enclosures, and underground conduits for relining structures under existing highways and railroads.
highway, railway, industrial, and municipal applications. Bridge Plank...For reflooring bridges and for new bridge
They are supplied in a variety of linings and coatings to construction.
meet specific durability and hydraulic requirements. Metric Sheeting...For trenches, cofferdams, shore protec-
HF..L-COR CL Pipe...Concrete.lined for top flow capacity tion, and cutoff walls.
plus proven strength of corrugated steel design. FLEX-BF. AM Guide Raii...A safety device for highways,
End Sections...A modern end finish for culverts and bridges, and parking lots.
sewer outfalis, either pipe or pipe-arch structures in A-2000 PVC Plpe...Profiled wall construction and
steel or aluminum, smooth interior for sanitary collector sewers
ULTRA FLO Storm Sewer Pipe...For improved hydraulic and small-diameter storm sewers. Meets ASTM F949.
capacity and light weight for storm sewers. ABS and PVC TRUSS PIPE...Combines strength, stiffness,
Slotted Drain...An efficient system for highways, parking joint integrity, and economy for gravity-flow sanitary
lots, or other surface drainage involving only narrow sewers. Meets ASTM D2680.
slots on the surface. Geos)~thetics...TENSAR Geogrids for soil reinforce- ~.,
Perforated Pipe...For subdrainage under airports, high- ment, base stabilization, slope reinforcement, and
ways, and railroads where the strength of steel is needed, retaining walls. TREVIRA Nonwoven Geotextiles and
HELCOR Pile ~hell...For foundations under buildings Contech Woven Geotextiles for drainage, separation,
filtration, and stabilization. STRIPDRAIN for highway
and bridges, edge drains and building foundation drainage. Contech
MULTI-PLATE Pipe, Pipe-Arch, and Arch...For bridges, ERO-MAT and Contech Excelsior Mat for erosion control.
stream enclosures, and storm sewers.
ContechConstructionProductslnc. · P.O. Box800 · Middletown, Ohio45042 ~\I~_.~,~T~IiU
Regional Offices are in the following cities:
At,an,a. GA30359 ............................................................ P.O. Bo, 49526 4o4,32 814 i
Houston. TX 77014 ...................... 14505 Torrey Chase Blvd., Suite 108 713/893-6012 CONSTRUC:TION PRODUCTS INC.
Indianapolis, IN 46250 ............................. 7164 Graham Road, Suite 120 317/842-7766
Memphis. TN 38157 ............................ 5050 Poplar Avenue, Suite 1028 901/761-3446
Oak Brook, IL 60521 .................................. ! 200 Harger Road. Suite 707 708/573-1 ! 10
Palmer, MA 01069 ..................................................................... Fenton St. 413/283-7611
Raleigh, NC 2';'609 ............................. 4700 Homewood Court, Suite 108 919/781-8540
San Bernardino. CA 92408 ........................... 1585 South D St., Suite 203 714/8~5-8800
Topeka. KS 66614 ........................................................ 5883 S.W. 29th St. 913/273-5950
Wheat Ridge. CO 80033 .................... 4891 Independence St., Suite 195 303/431-8999
Sales Offices are in principal cities.
NOTHING IN THIS CATALOG SHOULD IN ANY WAY BE
CONSTRUED AS AN EXPRESS WARRANTY OR AS EX-
TENDING TO THE READER OR BUYER ANY IMPLIED
WARRANTY INCLUDING BUT NOT LIMITED TO THE
IMPLIED WARRANTIES OF MERCHANTABILITY OR
FITNESS FOR ANY PARTICULAR PURPOSE. Specifications
and data referring to mechanical and physical properties
or chemical analyses relate solely to tests performed at
the time of manufacture on specimens obtained from '~
specific locations of the products in accordance with
prescribed sampling procedures. For specific terms and
conditions of sale, refer to standard Contech documents.
Contech. CORUX. FLEX-BF&M IJEL-COR. %IL LTl-PLATE. TblL'$$ PIPE and I.I.TRA FLO are
LP101 r.,,,,.., trad .... kso, C,.nlech C .......... '.,or.. Producls ,nc-¥2 ......... d.%'P£R-SPA.% are
5TRIPDR.AIN ~s a trademark o 4 TF.K t 1 D TENS.&R ts a reg:slt, r~-d tr..ten:ark. TREV]RA is a
EditionI ,.g.~,.r., Ifad .... k of Hoechst L'., ...... Corp
~ 1~91. Conlech Constr~lclion Pro~*.ucls Inc. Middleh)~*-n I. II!i,,
LCP-0362 (Reprint of LCP-0678) 7.5 CPF 9/91 L,Ih ..... L'.$ A